Quantifying Risk
Any human activity involves an element of risk
The exposure to sounds over 70 dB presents some risk to hearing function. The ambient sound levels of many city streets, public spaces, and transportation and the prevalent use of personal music devices, commonly exceed 70 dB. The following table estimates the risk associated with average 'volume levels' over a given exposure time.
Risk Comparison
when exposure is similar over a 40-hour week, over a working career
Ruling Body | Risk to hearing function | Average SPL | Exposure Time | Exchange Rate |
|---|---|---|---|---|
% | dB LAeq | Hours | dB | |
Workplace NZ, WHO | 8 | 85 | 8 | 3 |
OSHA (USA) | 25 | 90 | 8 | 5 |
The 2021 World Health Organisation's World Report on Hearing recommends that to avoid irreversible noise-induced hearing loss, exposure to loud sounds through leisure noise and personal audio devices should be limited to 80 dBA over 40 hours in a week for adults and 75 dBA over 40 hours in a week for sensitive users, e.g. children. The following table shows the WHO’s recommended maximum workplace exposure times for various sound pressure limits
WHO Noise Exposure Limit Recommendations
Average SPL (dB LAeq) | Exposure Time |
|---|---|
85 | 8 hours |
88 | 4 hours |
91 | 2 hours |
94 | 1 hour |
97 | 30 mins |
100 | 15 mins |
103 | 7.5 mins |
106 | 108 seconds |
SC - Audio Engineer / Sound Design - Hair - NASDA
There will always be a desire for good sound and a general lack of understanding in attaining it. So not everybody will just be able to throw together a sound system with any sort of good or even mediocre results.
Jim Long, Electro-Voice